Same here..depends on the application. We laminate almost everything and I commonly use a luster laminate. It's a happy medium between gloss and matte for our large outdoor advertising and backlit
signs. That way it doesn't look unfinished and has a bit of sheen without glare. I use it for most of our indoor decals as well as a default. However anything that is an indoor display like a pull-up banner is always matte. I also prefer to use matte scrim banner material no matter what. I find gloss looks cheap and shows more flaws over time on banners.
Vehicle graphics are always gloss. Unless the customer specifically wants a matte finish but I think that's more of a trend than anything.
It's easy to decide on the finish if you consider the
sign's purpose.
Vehicles are glossy so vehicle wraps are glossy. Pull up banners are usually under lighting so matte is preferred to reduce glare. Billboards are out in the sun so glare would be bad there too.
If you've considered the function and discovered that either finish would be acceptable then you would consider the artistic implications.
Matte has a more modern, serious feel. Gloss makes things pop and has a more playful feel.